Scatella fusca (Macquart 1835)

Scatella (Teichomyza) fusca Macquart

Teichomyza fusca Macquart, 1835:535.—Haliday, 1837:148 [review].—Schiner, 1863:268 [review].—Bezzi, 1892:41 [review].—James, 1947:154 [review].—Wirth, 1968:24 [catalog citation].—Papp, 1975:110 [review].

Ephydra longipennis Meigen, 1838:382 [synonymy by Schiner, 1863:268].

Teichomyza muraria Robineau-Desvoidy, 1848:xciv [nomen nudum; attributed to Macquart in discussion of Scatella urinaria].

Scatella urinaria Robineau-Desvoidy, 1848:xciv [nomen nudum; proposed as a replacement name for “murariaMacquart” (q.v.); synonymy by Schiner, 1863:268].

Tichomyza fusca.—Loew, 1860:45.—Becker, [unjustified emendation; review].—Becker, 1896:206 [review]; 1905a: 214 [catalog citation]; 1926:91 [review].—Nartschuk, 1970:386 [key].

DIAGNOSIS.—Mostly dark brown; middle coxa with patch of about 10 larger setae inserted anteroventrally; male middle femur with short row of 7–10 bristles along middle of posteroventral surface; male terminalia as in Figures 64–65.

DESCRIPTION.—Medium-sized to large shore flies, length 3.70 to 5.07 mm; generally appearing dull, mostly brown with some gray areas.

Head: (Figures 60, 61): Mesofrons and ocellar triangle rusty brown to blackish rust colored; fronto-orbits blackish; antenna, dorsum of interfoveal carina, and antennal fovea rusty brown, remainder of face becoming grayer; gena mostly blackish but usually with small, rusty colored area just below eye. Eye height-to-width ratio averaging 1:0.84; eye-to-cheek ratio averaging 1:0.33.

Thorax (Figure 62): Mesonotum blackish brown to grayish brown, becoming lighter colored posteriorly, with 2 bluish gray vittae along acrostichal tracks anteriorly, both fading and merging with surrounding color posteriorly; disc of scutellum gray to bluish gray, becoming brownish laterally; pleural areas, including notopleuron, mostly uniform in coloration, blackish gray with rusty background coloration becoming evident in less pollinose areas. Wing (Figure 72) length-to-width ratio averaging 1:0.44; costal vein index averaging 1:0.20; M1 + 2 vein ratio averaging 1:0.71. Middle, and to a lesser degree, male front femur with row of larger setae near middle along posteroventral margin, these particularly strong on middle femur; middle coxa with much stronger setae along anterior surface.

Abdomen: Mostly concolorous with mesonotum, but more thinly pollinose and more rusty brown in coloration. Male terminalia as in Figures 64, 65.

TYPE MATERIAL.—I have not studied the type or type series of the senior or junior synonyms. Macquart (1835) indicated that the type series of Teichomyza fusca included male and female specimens, and he stated that the species was “Commune en France.” According to Meigen (1838), the type series of Ephydra longipennis was collected by “Robert zu Ghenée” from near the city of Lütticher (Liege), Belgium. I have no data concerning the type series of Scatella urinaria Robineau-Desvoidy. The specimens of all three type series are probably in Paris or Lille, France.

SPECIMENS EXAMINED.—CHILE: Antofagasta Province: Antofogasta, Aug, at light, T. Cockerell (1; USNM). PERU: Moquegua Province: Ilo, at light, 9 Aug, T. Cockerell (2, 1; USNM). Ica Province: Pisco, on board Santa Inez, 16 July 1930 (2; USNM).

GEOGRAPHIC DISTRIBUTION.—This species has been collected from only three localities in western South America as listed previously, but I suspect that it will be found to be more widespread in the Neotropics when the specific habitat is more thoroughly collected. Wirth (1968:24) suggested that this species was introduced into South America by ship from Europe, but in view of the discovery that its probable sister group is from temperate South America, I suggest that the introduction was to Europe from South America, rather than the reverse.

NATURAL HISTORY.—Teichomyza fusca has frequently been referred to by the vernacular name “urine fly,” and the larvae and adults are generally encountered around outdoor urinals and excrement (James, 1947). Robineau-Desvoidy (1848) was apparently the first to observe this and belatedly reported it in responding to earlier inaccuracies of Macquart (1835), who mentioned that the fly is found on damp walls of old buildings and that the larvae feed among the decayed mortar. In this conjunction, Robineau-Desvoidy also stated that he had intended to describe this species under the Scatella urinaria because of their habit, and to make it the type of Scatella, but because of a printer's lapsis, his species did not appear in print.

Because of its propensity, this species has received greater attention than most shore flies from the standpoint of natural history. Laboulbène (1867) provided what is still the most detailed study of T. fusca, including descriptions and figures, albeit old, of the immature and adult stages plus observations concerning the life history. Subsequent studies by Vogler (1900), Johannsen (1935), and James (1947) are essentially recapitulations. Hennig (1952) included Teichomyza in his generic key to the larvae of Ephydridae.

This is the only species of Ephydridae that has been implicated to cause myiasis (James, 1947). Although numerous cases of urinary myiasis involving this species have been recorded, few, if any, have been confirmed. Chevrel (1909) discussed three cases of urinary myiasis in detail, but, as pointed out by James (1947), their authenticity was not clearly established. Evidence does implicate them, however, as causing facultative urinary or possible intestinal myiasis.

Three additional observations are of interest. Adults are apparently attracted to lights at night. The specimens Cockerell collected off the coast of western South America were taken “at lights.” Haliday (1837) and Bezzi (1892) both observed that adults were collected only during the winter (in Europe). Finally, during the middle nineteenth century, this species was reported to be extremely common in Paris (Laboulbène, 1867), but with the disappearance of outdoor urinals and other sites where highly organic water can accumulate, the fly has become less abundant.